Modern data processing apparatus more and more frequently relies upon solid state devices to perform the multitudinous functions required to process, store, utilize and retrieve information and data relative to business science and associated technologies. The printed circuit board and the dual in-line solid state circuit chip (DIP) have been married to produce a wide variety of useful data processing progeny, e.g., memory storage banks, central processor, oscillators, amplifiers, etc. The chips are, for the most part, fastened to the printed wiring board by rows of pins which are press fit into mating holes located in rows and columns on the surface of the printed circuit board.
Attachment techniques vary from manufacturer to manufacturer but they generally involve at least a printed wiring pattern and one or more multicontact chips. Each chip must be inserted into the wiring pattern and thereafter permanently secured therein. Solder is the most commonly used attachment medium and is applied by hand, or by means of solder machines or some combination of the two. Certain of the contacts of each chip may be bent or angularly oriented with respect to the printed circuitry effective to retain the chips for presentation to the solder stage of the fabrication technique being utilized. Thereafter the chips are permanently bonded in place and the circuit board is then ready for use.
Assuming no change in circuitry, or no failure of solid state chips, the foregoing is sufficient. However, should it be required or necessary for one reason or another to remove a chip and/or insert a replacement chip, a host of problems immediately present themselves.
A previous method for removing a chip component involved a heated plier type tool which gripped the chip for manual removal thereof from the board which action often cracked the board, dislodged the printed wiring pattern adjacent to the chip reception area or indeed, in some instances, severed one or more chip leads due to the forces required to detach the component from the board. Another method heated the bottom side of the printed wiring board with a pool of molten solder. Thereafter the operator utilizing a cold plier type tool pulled (from the top) the heat loosened chip from the board. This latter method often destroyed the board due to over-heating, loosened the adjacent printed wiring pattern and/or ruined the printed circuitry by premature pulling of the chip if the chip leads hadn't been sufficiently loosened by the applied heat.